At best it's a fable of "The Scorpion and the Frog" which is a classic fable about a scorpion asking a frog to carry it across a river. The moral is that some people cannot resist harming others, even if it goes against their own self-interest or destroys them both.

At worst it is premeditated exploitation to enrich oneself at the expense of those he has sworn an oath to do right by.